Real-time measurement of optical anisotropy during film growth using a chemical mist deposition of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)

Abstract

Real-time monitoring of optical anisotropy during growth by the chemical mist deposition of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films was carried out using spectroscopic ellipsometry. The microstructure of the grown films was found to be primarily determined by the DC bias applied to the mesh electrode. The ellipsometry results revealed that uniaxial anisotropy appeared for film thicknesses of about 5 nm and above, which corresponds to the average size of PEDOT crystallites. The extraordinary refractive index was found to be strongly correlated with the carrier mobility. Both the degree of optical anisotropy and the carrier mobility could be controlled during film growth by adjusting the DC bias.

Nafion-Modified PEDOT:PSS as a Transparent Hole-Transporting Layer for High-Performance Crystalline-Si/Organic Heterojunction Solar Cells with Improved Light Soaking Stability

“…The measured n and k spectra denoted by ⟨ n ⟩ and ⟨ k ⟩, however, include information on surface roughness and bulk inhomogeneity of PEDOT:PSS and c-Si substrate. So far, the optical constant of PEDOT:PSS and Nafion has been studied using a Tauc-Lorentz (TL) model and a Cauchy model described in following eqs and , respectively. , Here, a combination of a TL model, a Drude model, and a Cauchy model was used to explain the ⟨ n ⟩ and ⟨ k ⟩ spectra of Nafion-modified PEDOT:PSS to analyze film thickness d and optical constant of bulk and intermixing layer components with and without taking an uniaxial optical anisotropy into a consideration, i.e., bulk component spectra of // PEDOT:PSS (ordinary n 0 , k 0 ) and ⊥PEDOT:PSS (extraordinary n e , k e ). , A three-layer model was applied combining with the effective medium approximation (EMA) where A , C , E 0 , and E g represent the resonance amplitude, the oscillator broadening parameter, the resonance energy, and the Tauc optical band gap, respectively. E p and γ also denote plasma frequency and damping factor, respectively.…”

Effect of substrate bias on mist deposition of conjugated polymer on textured crystalline‐Si for efficient c‐Si/organic heterojunction solar cells

“…To these problems, the gas phase deposition such as spray coating and mist deposition has been extensively studied for uniform coating on textured c‐Si substrate. To date, we have attempted the film deposition of PEDOT:PSS on textured c‐Si substrate using chemical mist deposition (CMD) . The fine structure of PEDOT:PSS is determined by type of solvent, atomization frequency, nitrogen flow rate, substrate temperature T s , dc bias applied to the c‐Si substrate V s .…”

Printable and Semitransparent Nonfullerene Organic Solar Modules over 30 cm2 Introducing an Energy-Level Controllable Hole Transport Layer

“…Due to the formation of the h-HTLs, the O 1s atomic signal peaks of the PEDOT molecules became more enhanced compared to those of the PSS molecules (Figure S17b,c). In contrast, as shown in Figure a–c, the sulfur (S 2p) atomic signals of the pristine HTL Solar and h-HTLs showed the typical peaks of PEDOT (approximately 163.9 and 165.1 eV for S 2p 3/2 and S 2p 1/2 peaks, respectively) and PSS (168.7 eV for sulfur of thiophene) molecules. , With the use of WO 3 and MoO 3 , PSS peaks decreased significantly [h-HTL­(W): 21.66% decrease; h-HTL­(Mo): 16.57% decrease], and PEDOT peaks increased considerably [h-HTL­(W): 26.03% increase; h-HTL­(Mo): 33.26% increase] (Figure a–d). With the formation of h-HTLs, the stacking of the PEDOT molecules was enhanced, inducing the screen effect of the PSS molecules and a consequent increase in conductivity.…”

“…66 In contrast, as shown in Figure 4a−c, the sulfur (S 2p) atomic signals of the pristine HTL Solar and h-HTLs showed the typical peaks of PEDOT (approximately 163.9 and 165.1 eV for S 2p 3/2 and S 2p 1/2 peaks, respectively) and PSS (168.7 eV for sulfur of thiophene) molecules. 67,68 With the use of WO formation of h-HTLs, the stacking of the PEDOT molecules was enhanced, inducing the screen effect of the PSS molecules and a consequent increase in conductivity. Furthermore, the electrical resistivity and conductivity properties obtained through the four-probe measurements were 5.657 Ωm and 0.176 S m −1 , 4.718 Ωm and 0.212 S m −1 , and 3.424 Ωm and 0.292 S m −1 for pristine HTL Solar, h-HTL(W), and h-HTL(Mo), respectively.…”